1. Field of the Invention
The invention relates to non-refillable or single use valves for pressurized systems. The valve includes a valve housing mounted on the container, a valve body movable in the housing by means of a handle to allow and prevent release of fluid from the container. A nozzle is provided for venting fluid from the container.
2. Background Art
Pressure tanks or other pressure containers are usually filled under carefully controlled conditions at a charging station and then distributed to various places for use. Unfortunately, the attractive economies of refilling containers at points of use or otherwise repressurizing them under less than carefully supervised conditions has resulted, in the less consequential cases, in the introduction of impurities or inferior refills and, in the more consequential cases, to injurious explosions. The reuse of pressure containers is highly objectionable for many reasons which relate to safety.
U.S. Pat. No. 4,573,611 discloses a non-refillable valve for a pressure container which includes a housing. The housing has a central bore which has a lower portion that is narrower than the middle portion of the central bore and which has an upper portion that is narrower than middle portion of the central bore. A side port is present which communicates with the lower region of the middle portion of the central bore. The lower end of the housing is adapted to sealingly engage the pressure container in a manner which provides communication between the pressure container and the lower portion of the central bore. There is an outlet nozzle, having a bore lengthwise therethrough, which is positioned on the side of the housing which is in communication with the middle portion of the central bore via the side port in the housing. Valve stem means is positioned in the upper portion of the central bore in a rotatable manner which advances the valve stem means back and/or forth in the central bore. A tube is mounted on the internal end of the valve stem means which extends into the middle portion of the central bore. There is also a resilient valve sealing member which has a body portion and an upper flange that extends upwardly and outwardly from the body. A longitudinal passageway is present in the body portion, the bottom portion of the longitudinal passageway not extending through the bottom of the body portion. A vertical post is positioned in the middle of the longitudinal passageway, thereby forming a slot around the vertical post. The post slidingly engaging the tube on the bottom of the valve stem means. The flange portion of the sealing member is compressingly positioned in the upper portion of the central bore when the valve is inactive or being filled. The valve sealing member is pushed into the middle portion by means of the valve stem means when the valve is placed in the active position. The valve sealing member is seated against the interface between the middle and lower portions of the central bore when the valve is closed. The sealing member is positioned in the middle chamber above the seating interface when the valve is used for discharge of the container. The sealing member sealingly engages the seating interface when refill of container with pressurized fluid is attempted.
U.S. Pat. No. 4,543,980 discloses a valve for a pressurized container having a blocking element therein which is adapted to occupy an initial location in which fluid can move in and out of the container past the blocking element. The valve and blocking element are further configured such that the blocking element can be irreversibly moved to a position in which the valve permits escaped of fluid under pressure exerted from the inside of the container, but which automatically closes in response to exposure to an external pressure greater than the pressure inside the container. The blocking element is formed of at least one flexible, radially extending arm whose lateral radius is reduced upon movement of the blocking element from the initial location to the final location. The at least one arm expands within the final location to prevent return of the blocking element to the initial location.
German P No. 3,337,197 discloses non-refillable valves with a blocking element having at least one flexible arm. German No. '197 is a priority application of U.S. Pat. No. 4,543,980. German '197 also discloses embodiments of non-refillable valves which utilize ball-shaped sealing elements.
British Published patent application No. 2,133,502A and French Published patent application No. 2,536,818 appear to correspond to German 3,337,197.
U.S. Pat. No. 3,704,813 discloses a fluid dispersing valve assembly having a body one end of which is formed for securement to a container. The body forms a conduit having only one through passage for filling and discharging fluid. There is a shut-off valve operable for controlling the flow of fluid through the passage. The shut-off valve has an externally accessible control. There is convertible means in the body comprising an initially inactive check valve initially in condition to accommodate the flow of fluid through the passage in both the filling and discharge directions. The check valve is convertible after an initial filling operation into an active check valve in the passage in series with the shut-off valve. The initially inactive check valve includes a movable valve member, a valve seat, means for biasing the valve member toward the valve seat, and detent means effective initially to prevent the cooperation of the valve member with the valve seat. The detent means is defeatable after an initial filling operation to enable the valve member to engage the seat. The check valve when active is operative to pass fluid only in the discharge direction. The check valve after being rendered active to obstruct the flow of fluid selectively in the filling direction is guarded against access from the exterior of the valve assembly when secured to a container for reopening the passage to the flow of fluid in the filling direction Thereby a container equipped with the valve assembly can be evacuated and then filled with fluid in the initial condition of the valve assembly but is substantially non-refillable after conversion of the convertible means.
U.S. Pat. No. 3,985,332 teaches a non-refillable safety valve for a pressure container. The valve includes a housing, having a central bore, which provides communication between a port and the pressure container for charging and selective discharging the pressure container. The central bore has a lower portion that is narrower than the upper portion of the central bore. A hollow knob unit, having a central bore, is in threaded engagement with the outer wall of the housing. A core, having a central bore, is slidably mounted in the central bore of the housing. The upper end of the hollow knob unit is mounted on the core in a rotatable manner and in fixed longitudinal relationship with the core. A sealing member is slidably mounted in the lower end portion of the central bore of the core. The core contains end stop means for preventing movement of the sealing member below the lower end of the core. The sealing member engages the central bore of the housing when the core is moved the maximum possible distance into the central bore of the core or when refill is attempted after discharge of the pressure container. The core contains at least one passageway located in the core outwards form the sealing member for communication between the central bore of the core and said upper portion of the central core, of the housing. An engagable stop means is positioned between the outer surface of the housing and the inner surface of the hollow knob unit in order to limit retrograde or outward movement of the core to a position whereby the sealing member still engages the interface ledge when refilling the pressure container. The engagable stop means engages after the pressure container has been filled and the sealing member, the core and the knob unit have been moved into sealing position.
U.S. Pat. No. 871,780 teaches a bottle having a neck provided with a passage and having a valve chamber at the inner end of the neck. A valve seat is formed in the chamber. There is a valve operable in the latter and provided with a compressible head adapted to close upon the seat and of greater diameter than the passage. The valve is elastic, and is inserted into the chamber of the bottle by forcing it in deformed shape down the neck of a bottle by means of a mechanism similar to a screw press. The bottle is inserted into the press box and the screw is used to force the deformed valve down the bottle neck. The valve mechanism is used to prevent fraudulent substitution of contents; use with pressurized fluids is not mentioned.
There is a need for a relatively simple and inexpensive valve which will allow normal filling of the pressure container under proper conditions, adequate sealing of the pressure container during nonuse, selective discharge of the pressure container, and effective prevention of improper and unauthorized refilling of the container.
Check valves are old in the art. Concerning the flow of gases, U.S. Pat. No. 2,524,129 discloses a check valve wherein the top outside portion of valve 25 is cylindrical (24) and the bottom outside portion (23) is a truncated cone (with flat end 26). The bottom portion of valve 25 is therefore frustoconical in shape. Valve 25 also has top stem 27. (There are further parts to valve 25.) See the shape of the closure elements in FIGS. 1, 5, 7 and 9 to 11 of British Published Patent Application No. 2,088,317 (published on June 9, 1982) for non-refillable bottle stoppers. FIGS. 1 and 3 of British '317 show a round closure element and the shaped closure element 39 (although it is substantially hollow).